Patent GB-195127-A (GB)
Title: Improvements in and relating to the manufacture of hollow earthenware articles
IPC: B28B5/10
Filed: 1921-11-25
Abstract: 195,127. Leigh, E. W. Nov. 25, 1921. Cylinder machines; extrusion machines; cutting apparatus; delivery; lubricating.-Hollow-ware is moulded in a machine comprising a continuously rotating carrier head having a series of moulding cylinders therein successively filled with plastic material which is first compressed to form the base of the article, is then extruded on to a cradle to form its wall, and is finally cut off and dropped on to a conveyer. A pressure head rotates with the carrier head so as to close the cylinders and compress the material therein 'by toggle action. Clay is fed to the moulding cylinders 36 from a hopper 67 through a sector-shaped chamber 69 so arranged that as one filled cylinder leaves the chamber, the filling of the following cylinder has commenced. The upper part of the chamber 69 is provided with a valve 76, to allow excess clay to escape, and a scraper 77 to leave the surface of clay with a curved profile 78. The material is then compressed between pistons in the cylinders and caps carried by the. pressure head. The carrier head, Figs. 4 and 6 comprises a body part 25 secured by bolts 26 to vertical flanges of trunnion sleeves 21, 23 which are supported on bearings on uprights 22 carried by the machine frame 13, and are rotated by spur wheels 20. The pressure head is mounted on the same frame and is rotated in correlation with the rotary head by spur wheels 30, 31. The radial cylinders 36 each contain a piston rod 39 having a head 45 and a base 40. The head 45 is surrounded by concentric sleeves 51, 54, 55, the sleeve 51 carrying an interchangeable cap 49 adapted to mould the base of the article and being operated by a cam 34 having a friction roller 44 and surfaces 34a adapted to work on the recessed and offset portions 42a, 43 of the base 40, while the sleeve 54 is operated by cams 35, Fig. 4, so as to extrude the material to form the wall of the article. The cams 34, 35 are carried on a shaft 33 mounted eccentrically in a bush 32, and their throw can be adjusted by rotating the shaft 33 by means of a worm 157, an indicator 161 showing their position on a graduated disc 162 ; a second indicator may be provided to show the wear in the cam parts. Ports 47 communicating with openings 48 in the pistons 39 relieve the air pressure within the cylinders. The pressure head comprises a heavy disc having a central longitudinal opening and radial openings on its periphery which carry semi circular seatings 82, 83, arranged in pairs linked together by rods 88 and having corresponding oscillating members 84, 85, working in circular ribs 86. The latter fit in recesses in opposed faces of discs 28 attached to trunnion sleeves 29, Fig. 4. Each inner member 84 has a nosepiece 90 adapted to coact with a cam 92 on a shaft 93, and each outer member has a cap 81 which closes the ends of the cylinders 36 and moulds the bottom surface of the article, pressure being maintained on the clay both before and after central alignment of the corresponding recesses in the heads is reached. The distance between the heads is automatically adjusted so as to relieve ecessive pressure by mounting the trunnion sleeves 29 in bearings 94 controlled by a spring yoke consisting of springs 95 abutting against a collar 96 carried on rods 97, and by connecting the shafts 33, 93 by links 99 having eyes 100 larger in diameter than the eccentric ring 104 which they contain. After the base of the, article has been moulded, the outer surface thereof is trued by a spring knife 110. The partly moulded article is then extruded on to cradles each comprising a pair of plates 114 carried on pins 115 passing through flanges 116 of the discs 24 and attached thereto by springs 117. Each plate carries a cover plate which support on a bracket 132 a quadrant-shaped holder 133 and has sides 119, Fig. 10, forming a housing for a pair of crossed levers 120 fulcrummed on pins 121. The levers at one end carry on pins 128 parts 130 of a quadrant-shaped knife, the other ends 122 being forced inwards by leaf springs 126 and shaped to close round a lever 123 having a trip nose 125. After extrusion, stops 134 come into contact with the nose 125 and cause the knives to sever the material, a sflicing action being obtained by the cutter pins 128 sliding forward in recesses in the base plates 114. The steps 134, Fig. 3, are adjustably carried in slots 135 in a plate 136 which is pivoted at one end to a bracket 138 and secured at the other end by a spring to a bracket 140a. The secured article falls on to a conveyer 140 passing over a pulley 141 which can be adjusted to and from the carrier head by screws 146. The piston caps 50 and pressure plates 81 are burnished and oiled by rollers 166, 177, supplied with lubricant from troughs 172, 180. The quadrant, plates 133 are swung away from position by contacting with the lip 173 of the trough 172.